The present invention relates to a process for cleaning the door or door frame of a coking furnace, and particularly to such a process wherein a carriage equipped with cleaning instruments is mounted on a coke guide car structure. The carriage is propelled towards the door or door frame, and after they have been aligned, the cleaning instruments are caused to act against the surfaces requiring cleaning. The present invention further relates to an apparatus with which to carry out the aforementioned process.
The cleaning of coking oven doors is necessary, since the operation of coking furnaces leads to the formation of incrustations which have a deleterious effect on the furnace and which specifically can lead, among other things, to leakages around the door. For this reason, it is common practice to clean the coking oven doors after every discharge from the furnace chamber before reusing the furnace. The principle difficulties which are encountered in mechanical cleaning operations relate mainly to the fact that satisfactory cleaning requires small tolerances between the surfaces to be cleaned and the cleaning instruments, while at the same time the displacement of the door and the movement of the carriage or rig carrying the cleaning instruments requires large tolerances.
The great height of the furnace door adds to the difficulties, as does the fact that the cleaning instruments must be applied with relatively great pressure in order to remove the crust formations. This pressure must not, however, be anywhere near great enough to cause deformation or other damage to the door or door frame elements.
German DT-AS No. 1,147,914 describes a device for cleaning the edge seal of a furnace door wherein, in order to align the rig to any given door opening, the rig is freely suspended about a horizontal axis of rotation. In addition, compression springs are provided to act in the direction of the center of rotation and to produce an elastic mounting of the rig and an elastic counter-pressure where the rig and door stoppers join. In this system the arrangement between rig and door is an improvement over a rigidly mounted rig. However, there still remains the difficulty that the height of the axis of rotation relative to the door must be exactly predetermined, since otherwise the cleaning of the upper and lower edge seals of the door is impaired. Another disadvantage is due to the fact that the springs continuously exert pressure when, in fact, during the actual cleaning operation a rigid combination of door and rig is desired.
German DT-OS No. 1,671,332 describes a device for cleaning a coking oven door wherein the rig carrying the cleaning instruments is mounted on a universal joint. This allows the rig to carry out light rocking movements, so that in the event of the door being tilted, the rig can adjust to the position of the coking oven door.
In this system also, the position of the rotating axes of the universal joint relative to the door must be exactly predetermined. This is difficult to achieve, since the tolerances between the position of the door and the rig drive mechanisms can be determined only with the greatest difficulties.
In all the existing systems and processes, it is disadvantageous that the rig for cleaning the coking furnace door must be driven or tracked against the door, and that there exists no direct connection between the carriage drive and the displaced or drafted door.